Polyesters of fluorinated glycols and phthalic acids



United States Patent POLYESTERS OF FLUORINATED GLYCOLS AND PHTHALICACIDS Donald D. Smith, Nlidland, Mich., assignor to Dow CorningCorporation, Midland, Mich., a corporation of Michigan No Drawing.Application May 17, 1956 Serial No. 585,384

1 Claim. (Cl. 260--75) This invention relates to novel fiuorinatedpolyesters of glycols and phthalic acids.

It is the object of this invention to prepare novel compositions ofmatter which are useful as thermally stable insulating varnishes andcasting resins. Other advantages will be apparent from the followingdescription.

This invention relates to polymeric compositions of matter having theunit formula in which n is an integer of at least one and R is aphenylene radical.

The compositions of this invention are prepared by reacting fluorinatedglycols of the formula with a phthalic acid, a phthalyl halide or loweraliphatic esters of phthalic acids. The reactions can be carried out inthe conventional manner for forming polyesters. The conditions will varydepending upon whether a phthalic acid or an acid chloride are employed.In general, reaction temperatures of from 100-200 C. give satisfactoryresults.

The glycols which are employed as starting materials in this inventioncan have any number of perfluoromethylene radicals in the chain.Preferably n has a value from l-5. Glycols of this type are known andare generally prepared starting with the corresponding1,2-dichloroperfluorocycloalkene, oxidizing the double bond to adicarboxylic acid and then reducing the dicarboxylic acid to the glycol.

For the purpose of this invention the glycol can be reacted with anyphthalic acid such as terephthalic, isophthalic or phthalic acids andtheir ester forming derivatives such as terephthalyl chloride,isophthalyl chloride, dimethyl terephthalate or diethyl isophthalate.

The products of this invention exhibit excellent thermal stability andare useful both as thermoplastic resins and as thermosetting resins. Oneexpeditious way of thermo- 2,902,473 Patented Sept. 1, 1959 setting theresin is to react the polymers with a diisocyanate such as toluenediisocyanate.

The following examples are illustrative only and should not be construedas limiting the invention which is properly delineated in the appendedclaims.

Example 1 7 parts by weight of 2,2,3,3,4,4-hexafluoro-1,S-pentane- 8parts by weight of this polymer were mixed with .08 part by weighttoluene diisocyanate and .05 part by weight water and heated to effectsolution. The melted mixture was heated at C. under a pressure of 5,000p.s.i. for 15 minutes. The resulting material was a tacky mass whichupon standing set to a hard, tough, insoluble solid.

This material is useful for coating electrical conductors and forprotective coatings for metals.

Example 2 When the glycol HOCH (CF CH OH is reacted with an equivalentamount of dirnethyl isophthalate by heating the mixture at a temperatureof 150 C. under conditions which allow methanol to escape, athermoplastic polymer having the unit formula [OCH (CF CH OOCC H CO] isobtained.

Equivalent results are obtained when isophthalic acid is employed inlieu of its methyl ester.

That which is claimed is:

A resinous polymeric composition of matter having the unit formula[-OCH2 (CF CHgOOCRCO-J in which n is an integer of from one to fiveinclusive and R is a phenylene radical.

References Cited in the file of this patent UNITED STATES PATENTS2,465,319 Whinfield et al. Mar. 22, 1949 2,568,501 Husted et al Sept.18, 1951 2,585,827 Padbury Feb, 12, 1952 2,697,087 Hetzel Dec. 14. 1954

